In preparation to pull the trigger for a new set of wheels I bought one 18 x 10 American Racing Torq Thrust II VN215 with matte gray center to use as a test-fit wheel. I had a 265/40R18 tire mounted on it and it worked perfectly to verify the correct backspacing I needed for the new wheels. It has a +6mm offset (5.75" backspace) which is more backspacing than most people would be willing to run on a stock car. However, I was able to use a few other tools to confirm how much I needed to adjust to get the clearance I needed. This test fit was done on my '69 with 2" CIC flares on all four corners.

To check the fronts I used a 1.25" wheel adapter to simulate a 4.5" backspace. I checked both sides and found that I had plenty of clearance at full lock. With the wheel turned all the way in I had 7/8" clearance to the stock sway bar and 1" clearance to the nose support bracket. With the wheel turned all the way out I had 3/4" clearance to the frame rail. So with an 18" wheel I could have gone for 5" backspacing and probably not had any contact, but the 4.5" BS gave me the right relationship to the fender that I wanted, so I left it at that.












For the rear I used some 0.2" thick washers to approximate a 5.5" backspacing. With the spacers I found that I had 3/8" clearance to the leaf spring bolt and 1/4" clearance to the frame kick-up, but I did have a slight interference with the parking brake bracket on the trailing arms. With just a little grinding on that bracket I could have run 5.5" BS without any concern, but I opted to push the wheel a little further out to fill the wheelwell a little more and went with 5.375" BS.











If anyone has interest in this wheel for test fitting purposes or for actual use on their car just let me know. It's basically pristine having only had a tire mounted and un-mounted one time. No road miles whatsoever. I'll cut you heck of a deal!

 

Instead of washers just buy the. 25 spacers from summit racing by

 

I could probably use a spare, those are the exact wheels that I use (with 0.2" spacers) as track wheels front and rear on my car. Don't know what sort of price you could get for shipping to Australia... I would buy it at the right price including shipping though

 

I see that tire is a little over 26 inches in diameter. Do you think with a 27 inch diameter tire you could have run 5.75 inch backspace without hitting the frame in the front? Trying to figure mine out now. I am going to run a 27 inch tire. Thanks for the info!

 

I'm not the OP, but nope, I don't think so. These cars do vary so you really need to measure your own car. The larger diameter the tyre the more the clearance to the frame in front of the rear wheel is an issue. Some people have cut out the offending section of frame (the brace for the trailing arm pocket) and boxed it for additional clearance. It does depend though on the width of your wheel and tyre - as an extreme example, a 265 on a 13" wide wheel would probably fit fine with a 5.75" backspace as it would be stretched away from the frame.

 

I couldn't have run a 5.75" BS on either front or rear without rubbing, regardless of tire diameter. To MetalHead's point there's a certain amount of variation from car to car. That's why it was worth the couple hundred bucks to buy this "test-fit" wheel to verify everything before finalized dimensions for the set of wheels I really wanted.